Byron picks up where he left off and shows us Don Juan sleeping with his head resting on Haidée's chest.
By the time Byron published this canto, the world has seen his first two and there had been plenty of reaction to how immoral they were. So Byron defends himself by saying that he's simply a storyteller. His characters can do whatever they want, and if people want to blame them then they should blame the characters and not Byron.
So it looks like Don Juan is living a sweet life with his rich sweetheart. So now it's time for Byron to throw some conflict into the mix. Enter Haidée's pirate father, who returns home after a long journey at sea.
The father (named Lambro) returns home to find the place has been turned into party central. Haidée has basically given the servants free rule over the place. There are drunken people everywhere and bands playing dance songs. What he doesn't realize is that everyone is partying because they think he has died at sea.
Lambro tries to politely ask a few servants what's going on. They don't recognize him and tell him it's party time. Woooo! A second one tells him that everyone's celebrating because their master Lambro has died. Now Lambro is starting to get mad. He hides it, though, until he can learn the full story.
He eventually comes upon Haidée and Don Juan, who are dressed in super-expensive clothes that have clearly been bought with Lambro's money.
Before Lambro can say anything, a small poet dances into the center of the room and reads a poem. This also inspires a digression by Byron about the meaning of art and life in general. He returns to his general theme that life is short and there's no point in trying to be remembered. So why not enjoy the time you've got?
Just when Byron acknowledges his own digression, he falls back into another huge digression. And before you know it, the canto has ended and we don't even know whether Haidée realizes that her father has come home.